BMW M54 6-cylinder – White Smoke From Exhaust – X5 and Others – Crankcase Ventilation – PCV ?
Q I have an ’02 X5 3.0i. When I start the vehicle, white smoke comes out of the exhaust. Is it just moisture? Is it from a bad oxygen/fuel mixture? If so, do I need a new oxygen sensor? I’ve also recently had to add about 3 quarts of oil every 2-3 months in between oil changes. Any help would be appreciated.
A The amount of oil usage that you’ve noted is on the excessive side. You may have a clogged crankcase ventilation system. Late model, 6-cylinder engines have a problem with the crankcase ventilation system getting clogged with oil sludge and moisture. The oil separator and hoses commonly get clogged up due to the long time between the BMW-recommended intervals for oil changes, plus the build up of moisture due to normal condensation, which can cause sludge build-up or freezing in the oil separator and oil drain hose. This is a very common issue and the typical symptom is increased oil usage. The cure is to disassemble all of the hoses and replace the oil separator (refer to the diagram below). Also, we have found that the hoses are usually hardened and tend to crack when removed. It is therefore a good idea to replace all of the hoses as well. The hoses and oil separator are found under the intake manifold. This procedure is not covered in the Bentley repair manual for the X5 00 thru 06 (#BX56). See our blog post, below, for a full DIY.